Question

Among the following, van der Waals forces are maximum in:

• A. $HBr$
• B. $LiBr$
• C. $LiCl$
• D. $AgBr$

Answer 1

The correct option is D $AgBr$

van der Waals forces are maximum for large size anions and small size cations. van der Waals forces are directly proportional to the molecular weights. All the bonds in $HBr,LiCl$ and $AgBr$ are polar bonds.
van der Waals force depends on the number of electrons in each element. So, heavier the element, higher will be the force.
van der Waals forces $\propto$ molecular weight.
As the size of $A{g}^{+}$ and bromide ion are the largest, $AgBr$ will have the greatest van der Waals forces among the given options.